// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_BROWSER_SPEECH_SPEECH_RECOGNITION_DISPATCHER_HOST_H_
#define CONTENT_BROWSER_SPEECH_SPEECH_RECOGNITION_DISPATCHER_HOST_H_

#include <memory>

#include "base/macros.h"
#include "base/memory/weak_ptr.h"
#include "content/common/content_export.h"
#include "content/public/browser/browser_message_filter.h"
#include "content/public/browser/speech_recognition_event_listener.h"
#include "net/url_request/url_request_context_getter.h"

struct SpeechRecognitionHostMsg_StartRequest_Params;

namespace content {

class SpeechRecognitionManager;

// SpeechRecognitionDispatcherHost is a delegate for Speech API messages used by
// RenderMessageFilter. Basically it acts as a proxy, relaying the events coming
// from the SpeechRecognitionManager to IPC messages (and vice versa).
// It's the complement of SpeechRecognitionDispatcher (owned by RenderView).
class CONTENT_EXPORT SpeechRecognitionDispatcherHost
    : public BrowserMessageFilter,
      public SpeechRecognitionEventListener {
public:
    SpeechRecognitionDispatcherHost(
        int render_process_id,
        net::URLRequestContextGetter* context_getter);

    base::WeakPtr<SpeechRecognitionDispatcherHost> AsWeakPtr();

    // SpeechRecognitionEventListener methods.
    void OnRecognitionStart(int session_id) override;
    void OnAudioStart(int session_id) override;
    void OnEnvironmentEstimationComplete(int session_id) override;
    void OnSoundStart(int session_id) override;
    void OnSoundEnd(int session_id) override;
    void OnAudioEnd(int session_id) override;
    void OnRecognitionEnd(int session_id) override;
    void OnRecognitionResults(int session_id,
        const SpeechRecognitionResults& results) override;
    void OnRecognitionError(int session_id,
        const SpeechRecognitionError& error) override;
    void OnAudioLevelsChange(int session_id,
        float volume,
        float noise_volume) override;

    // BrowserMessageFilter implementation.
    void OnDestruct() const override;
    bool OnMessageReceived(const IPC::Message& message) override;
    void OverrideThreadForMessage(const IPC::Message& message,
        BrowserThread::ID* thread) override;

    void OnChannelClosing() override;

private:
    friend class base::DeleteHelper<SpeechRecognitionDispatcherHost>;
    friend class BrowserThread;

    ~SpeechRecognitionDispatcherHost() override;

    void OnStartRequest(
        const SpeechRecognitionHostMsg_StartRequest_Params& params);
    void OnStartRequestOnIO(
        int embedder_render_process_id,
        int embedder_render_view_id,
        const SpeechRecognitionHostMsg_StartRequest_Params& params,
        int params_render_frame_id,
        bool filter_profanities);
    void OnAbortRequest(int render_view_id, int request_id);
    void OnStopCaptureRequest(int render_view_id, int request_id);
    void OnAbortAllRequests(int render_view_id);

    int render_process_id_;
    scoped_refptr<net::URLRequestContextGetter> context_getter_;

    // Used for posting asynchronous tasks (on the IO thread) without worrying
    // about this class being destroyed in the meanwhile (due to browser shutdown)
    // since tasks pending on a destroyed WeakPtr are automatically discarded.
    base::WeakPtrFactory<SpeechRecognitionDispatcherHost> weak_factory_;

    DISALLOW_COPY_AND_ASSIGN(SpeechRecognitionDispatcherHost);
};

} // namespace content

#endif // CONTENT_BROWSER_SPEECH_SPEECH_RECOGNITION_DISPATCHER_HOST_H_
